ITW paktron blue drops.

[dragonbat13]

Anybody have any data sheets or know if they were polypropylene, polyester or some other dielectric?

[B Ingram]

... know if they were polypropylene, polyester or some other dielectric?

Judge the dielectric by the size of the cap.

For the same value, Mica/Polystyrene is larger than Polypropylene is larger than Polyester is larger than Aluminum Electrolytic.

Based on the size, I'd guess they were polyester like most of the rest of Fender's 0.022 to 0.1µF caps.

Note that "plate area" is what matters in a cap. So a long & skinny "blue molded cap" using polyester is one form-factor, while the brown "chocolate drop" caps also using polyester are a different form-factor while having the same capacitance & voltage rating.

[dragonbat13]

Thanks.

I have a 72 silver face twin that has a bunch of orange drops I put in it a long time ago. I lost the blue drops.

I'm not interested in going the NOS or good used drama. I just as soon find something comparable to what was originally in it.

[jelle]

Polyester, the CDE 6PS orange drops will work, jelle

[nuke]

Thanks.

I have a 72 silver face twin that has a bunch of orange drops I put in it a long time ago. I lost the blue drops.

I'm not interested in going the NOS or good used drama. I just as soon find something comparable to what was originally in it.

They're epoxy coated metalized mylar (polyester). Mallory 150 would be a like replacement. Mojotone "Dijon" polypropylene have somewhat better electrical characteristics than mylar. Both are bright yellow. The mylar will be smaller, the polypropylene are physically bigger.

I like cylindrical axials like the 150M or the Mojotones for eyelet and turret boards vs Orange drop or other dipped styles. It is easier to break the epoxy coating bending the leads of the dipped type, and they don't have as much mechanical strength hanging by the leads. Use orange drops on printed circuit boards.

[dragonbat13]

I've got a marshall build with Mallory 150. I'm going to do this year, hopefully. I have the whole kit built up. I just am between places at the moment.

I'll see how I like that, but since Mallory 150 seems to be a good compromise to full on nos blue drops I may go that route.

I'm in the same boat, I'm big on component stability too. Once I get to building my own boards I'm gonna try the eyelet/turret setup to keep lead bending at the component attachment to a minimum. I'm also gonna take a stab at lead restrain bends. Or whatever it's called.

But even that gets somewhat questionable with the completely flimsy leads common today. I get it, they are designed for modern PCB construction.

Thanks for the info.

[TUBEDUDE]

All of the.above caps are Metalized film. The orange drops are actuall a metal foil wound between layers of poly.. 716P's use polypropylene, they are brighter and the 6PS are polyester, duller, good for taming top end.

[nuke]

The CDE catalog of "orange drops" has both, polypropylene and polyester and both types can be film-and-foil construction or metallized film. They're also offered in cylindrical or pressed construction and with pre-bent or straight leads and other typical catalog options for similar capacitors.

To be honest, in most tube guitar amp circuits, the difference between polyester and polypropylene dielectric are so small as to be negligible. Foil construction offers higher peak current operation than metallized film - again, not usually important in guitar amp circuits. Polyester (aka Mylar) capacitors are smaller and less expensive than polypropylene. Electrically, polyester has higher dielectric absorption than polypropylene. In most tone control and coupling applications, there's not much difference between them.

FWIW, correctly chosen ceramic capacitors also can work well in many applications, although many types are microphonic or exhibit non-linearity and can induce distortion.

As a recipe ingredient, I've not found a "characteristic sound" of any of them, assuming they're appropriate for the particular circuit application. I tend to go with polypropylene in audio circuits as my default choice, "...'cause there ain't a better one" and I'm not ordering tens of thousands of them. But in the typical audio path application, there isn't a critical difference between poly-films or foil vs. metalized.